II 



PHYLUM PROTOZOA 



85 



In some of the Coccidiidea this life cycle is modified in various ways, as, for 

 example, by the omission of schizogoiiy the trophozoites in such a case 

 developing directly into gametocytes. 



Fio. 65. Life-History of Coccidium schubergi. a. penetration of epithelium cell of host by 

 sporozoite ; b-c, stages of multiple fission (schizogoiiy) ; d, gametocyte ; e, f, formation of 

 megagamete (ovum) ; g, fertilisation ; h, j, formation of microgarnetes (sperms) ; k, develop- 

 ment of fertilised ovum into four spores ; I, formation of two sporozoites (falciform young) in 

 each spore. (From Calkins, after Schaudinn.) 



ORDER 3. H/EMOSPORIDEA. 



These are Sporozoa which in the trophozoite condition live as parasites in 

 the interior of the coloured blood-corpuscles of all classes of Vertebrates, but 

 are occasionally found in other cells. In Man and in some other mammals and 



